The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
In an increasingly wireless world, antennas are becoming ever more prevalent. This is particularly true in automobiles, which typically include antennas for receiving signals associated with one or more of AM radio, FM radio, satellite radio, cellular phones, and Global Positioning System (GPS).
By way of example, FIG. 1 schematically illustrates an antenna system 10. As shown, the system 10 includes a first patch antenna 12 tuned to a first center frequency fc1. The system 10 also includes a second patch antenna 14 tuned to a second center frequency fc2. In some embodiments, the first center frequency fc1 may be a frequency used by the Satellite Digital Audio Radio Service (SDARS) (e.g., 2.320 GHz to 2.3325 345 GHz for SIRIUS Satellite Radio Service, 2.3325 GHz to 2.345 GHz for XM Satellite Radio Service, etc.), and the second center frequency fc2 may be a frequency used by the Global Positioning System (GPS) (e.g., at least 1.575 GHz, etc.).
As shown in FIG. 1, a first low noise amplifier (LNA) 16 amplifies the signal from the first patch antenna 12. A second LNA 18 amplifies the signal from the second patch antenna 14. Signals from the first LNA 16 and the second LNA 18 communicate with inputs of respective band pass filters (BPF) 20, 22 that have center frequencies at fc1 and fc2, respectively. A first amplifier (AMP) 24 amplifies the signal from an output of the first band pass filter 20. A second amplifier 26 amplifies the signal from an output of the second band pass filter 22.
A first receiver 28 receives the signal from the first amplifier 24. In some embodiments, the first receiver 28 may be a SDARS receiver that is compatible with SIRIUS satellite radio and/or XM satellite radio broadcast signals. A second receiver 30 receives the signal from the second amplifier 26. In some embodiments, the second receiver 30 may be a GPS receiver or transceiver that includes a display and/or user interface.
The first patch antenna 12, second patch antenna 14, first LNA 16, second LNA 18, first band pass filter 20, second band pass filter 22, first amplifier 24, and second amplifier 26 may be assembled into a compact antenna assembly 32. The antenna assembly 32 may be suitable for mounting on a structure, such as a motor vehicle roof, trunk, inside the instrumentation panel (IP), etc.
Coaxial cables may be used for making the connections between the first amplifier 24 and the first receiver 28 and between the second amplifier 26 and the second receiver 30. The first LNA 16, second LNA 18, and coaxial cables tend to be fairly expensive when compared to the costs associated with the other elements of the antenna assembly 32.